Nowadays, liquid crystal materials are widely utilized in various liquid crystal displays having different sizes for different applications, such as TVs, liquid crystal projectors, mobile telephones, personal digital assistants (PDA), etc. Because liquid crystal itself cannot emit light, light sources must be utilized to illuminate liquid crystal for image display. The light sources are called backlight sources since they are usually configured behind liquid crystal panels. A combination of all components behind the liquid crystal panels, including the light sources, is generally referred to as a backlight module. Usually, the backlight modules can be classified into edge type backlight modules and direct type backlight modules.
A typical direct type backlight device includes a light guide plate and a plurality of light sources arranged behind the light guide plate. Because the plurality of light sources are arranged behind the light guide plate, the regions of the light guide plate adjacent to the light sources are brighter than those further away from the light sources. Thus brightness uniformity of the direct type backlight device is impaired. One method for solving this problem includes adding an amount of light sources, but this will produce new problems, such as high cost and over-heating. It cannot satisfy needs of the high quality of direct type backlight devices and liquid crystal displays.
What is needed, therefore, is a direct type backlight module with high brightness uniformity and a corresponding liquid crystal display.